package com.hmdp.utils;

import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;
import java.util.concurrent.TimeUnit;

@Component
public class RedisIdWorker {
    // 开始时间
    private static final long BEGIN_TIMESTAMP = 1735660800L;
    private static final int COUNT_BITS = 32;

    private final StringRedisTemplate stringRedisTemplate;

    public RedisIdWorker(StringRedisTemplate stringRedisTemplate) {
        this.stringRedisTemplate = stringRedisTemplate;
    }

    public long nextId(String keyPrefix) {
        // 1.生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);
        long timestamp = nowSecond - BEGIN_TIMESTAMP;

        // 2.生成序列号
        // 2.1.获取当前日期，精确到天
        String date = now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        // 2.2.自增长
        long count = stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + date);
        stringRedisTemplate.expire("icr:" + keyPrefix + ":" + date, 24, TimeUnit.HOURS);

        // 3.拼接并返回
        return timestamp << COUNT_BITS | count;
    }

    public static void main(String[] args) {  // 模拟获取时间戳
        // 时间戳开始时间
        LocalDateTime time = LocalDateTime.of(2025, 1, 1, 0, 0, 0);
        // 设置时区
        long seconds = time.toEpochSecond(ZoneOffset.of("+8"));
        System.out.println("second = " + seconds);
    }
}
